If you are using the Business Central cloud based service, your logins URL is https://businesscentral.dynamics.com + /tenantId + /environment name. Typically you don't need the tenantId or environment name. Business Central (BC) can figure that out from your Azure login.
If you are on a On-Premise version, or use an Azure virtual machine (a form of on-premise install) then things can get complicated. A single server install is simple. Your login URL will be the address to that server + /BC or + /BCXXX (if defaults were selected). The XXX should be replaced with the BC version, for example version 19 would be 190. If you are in a two or three tier setup where the BC service is running on a different computer than the web server (IIS), then you need to know the URL to the web server (IIS) to login using a browser.
If on the other hand if you need to connect VS Code to BC on-premise, you need the URL for the BC server. Most likely this will be a http connection (that is the default) where as the browser login connection is over https.
If you have a test / dev instance running on the same server as your production server, you will need the correct port as the two services cannot share the same port.
Hope this helps, as I have often needed to look this up to remind my self of how these things come together.